Grinding mill



y 1941- e. A. CAMPHUIS 2, 42,109

GRINDING MILL Filed March 13, 1939 2 Sheets-Sheet 2 m2 a zm ims Patented May 13, 1941 UNITED STATES PATENT OFFECE GRINDING MILL George A. C'amphuis, Los Angeles, Calif.

Application March 13, 1939, Serial No. 261,625

4 Claims.

This invention relates to peripheral discharge grinding mills which may be termed either screening ball mills, screening rod mills or screening tube mills, and the grinding medium employed maybe pebbles, metal discs or irregular pieces of metal, metal balls, rods or tubes, porcelain balls or grinders formed from any other suitable hard compound.

The object of my invention is to provide, in a manner as hereinafter set forth, a mill of the class referred to which is distinctive by its novel and sturdy construction which makes possible its prolonged use without breakage and provides unusual uniformity of grain in the ground prodnot desirable in industries.

A further object of my invention is to provide, in a manner as hereinafter set forth, a mill of the class referred to to grind rock matter, rock-forming minerals, metallic or non-metallic ores and compounds, or other materials or sub- I stances required to be ground or pulverized for use in the industries or for metallurgical or chemical processes; or for grinding or cleaning grain or any product of vegetable life; all of which may be accomplished in conjunction with or without air pressure, or suction to collect dust or fine material in suspension during the grinding. Grinding may be with water, chemical solutions, or dry,

A further object of my invention is to provide, I

in a manner as hereinafter set forth, a grinding mill of the class referred to whereby the material to be acted upon may be disintegrated by impact, scuffing, abrasion, or chemical process, or other desirable means within a horizontally disposed revoluble cylindrical grinder structure and with the discharge of the result of action had from the outer periphery or outer surface of such structure. i

A further object of my invention is to provide, in a manner as hereinafter set forth, a grinding mill of the class referred to whereby the material ground thereby will be discharged at the outer periphery or .outer surface of the ginder structure aforesaid and will be subjected to a progressive screening action as it travels to the point of discharge.

A further object of my invention is to provide, in a manner as hereinafter set forth, a grinding mill so constructed and arranged whereby it provides an effective mechanical method for allowing escape of ground material away from the grinding medium as soon as it has attained the desired fineness of grain to pass the ruling size of an outer screen, the unscreened material which has not attained the desired fineness continuously being carried around to fall back into the grinding medium from the top of the grinder structure while revolving, as such material falls back readily from the rising part of the grinder structure by virtue of the screening means being formed with openings of increasing width or diameter toward the center of the mill, and with the clearing of the material not discharged from the screening means being assisted by the vibration from the revolving and tumbling of the grinding medium.

A further object of my invention resides in the providing of the grinder structure with an inner and an outer screen disposed coaxially; the manner in which the inner screen is arranged relative to the body part of such structure; and the manner in which the screens are secured on the body of said structure.

Further objects of my invention are to provide, in a manner as hereinafter set forth, a mill for the purpose referred to which is comparatively simple in. its construction and arrangement, strong, durable, compact, readily assembled, thoroughly efficient in its use, readily repaired when occasion requires and comparatively inexpensive to produce.

Embodying the objects aforesaid and others which may hereinafter appear, my invention consists of the novel construction, combination and arrangement of parts as will be more specifically referred. to and as illustrated in the accompanying drawings, wherein embodiments of the invention are shown, but it is to be understood that changes, variations and modifications may be resorted to which fall within the scope of the invention as claimed.

In the drawings:

Figure l is a front elevation of the mill partly in vertical section and partly broken away,

Figure 2 is a view in elevation looking towards the outer face of a head of the mill and illustrating such head provided with attaching means for grid element bar fasteners of the form shown by Figure '7, I

Figure 3 is a view in front elevation of a modified form of grid element bar,

Figure 4 is an end view of the structure shown in Figure 3,

Figure 5 is a section on line 5-5, Figure 1, with certain parts omitted,

Figure 6 is a section on 6, Figure 3,

Figure 7 is a sectional detail of a modified form of attaching means for a grid element bar,

- Figure 8 is a sectional detail of another modified form illustrating a modified form of cylinder head and attaching means for a grid element bar,

Figure 9 is a detail in side elevation of one of the members of the attaching means shown by Figure 8, and

Figure 10 is a sectional detail of one of the main bearings.

The grid element shown by Figures 1, 5 and '7 is indicated generally at M and that shown by Figures 3, 4, 6 and 8 at N. The elements are of like form, with this exception, that the slots or openings I, 2 in element M are of a difierent form than the form of the slots or openings 3, 4 in element N. The slots I are of the same form as, but of less length than the slots 2. The slots 3 are of the same form as, but of less length than the length of the slots 4. The said several slots are disposed lengthwise of the body of the grid. The side walls of the slots 3 are formed with a single projection 5. The projections 5 on the side walls of each slot 3 are oppositely disposed. The side walls of the slots 4 are formed with a plurality ofspaced projections 6 and I. The projections 6 are oppositely disposed with respect to the projections I. Otherwise than that as stated aforesaid, the grid elements M and N are of like construction and with respect to the hereinafter description of the grid elements, it is to be understood that the description of one will apply to the other.

The grinding or disintegrating medium is shown by way of example as consisting of a mass of independent metallic globular bodies 8. It is to be understood that the grinding or disintegrating medium may be as desired.

The mill includes a horizontally disposed revoluble cylindrical grinder structure providing a disintegrating or grinding chamber 9 in which the material to be acted upon is supplied. The bodies 8 are arranged in chamber 9. The grinder structure is of the knockdown type and it includes a pair of oppositely disposed flanged trunnioned heads ID of like form, sectional liners I2 for the end walls of chamber 9 and a grid element M or N mounted on said heads.

Each head I consists of a circular body part I3 formed with an axial opening I4 and a hollow trunnion I merging at its inner end into the wall of opening I4. The trunnion I5 extends outwardly from body part I3, and is formed of inner and outer portions I6, I! respectively. The portion I6 has its inner and outer diameters greater than the inner and outer diameters of the portion I! whereby the trunnion is formed with a peripheral shoulder I8. The head II) also includes an annular flange I9 of angle-shape cross section to form a horizontal leg 20 and a vertical leg 2 I. The leg 20 is integral with and flush with the inner face of said body part I3. The leg 20 at its outer end merges into the inner end of the leg 2I. The latter is disposed in outwardly extended relation with respect to the outer edge of body part I3. The leg 20 constitutes a seat for a purpose referred to and has its outer face formed with an annular groove 22. The leg 20 is also formed with spaced aligned openings 23 which communicate with groove 22. The purpose of the groove and openings 23 will be hereinafter referred to. The vertical leg 2I has its inner side face formed with a row of spaced inset tapered seats 2|, and such leg is also formed with a row of spaced transverse openings 2I which extend from its outer face to the seats 2 l trated in Figures 1 and 7. Only one of the openings is shown and it is illustrated in Figure 7.

Only one of the seats is shown and it is illus- The inner diameter of the hollow trunnions I5 is such, as to permit of a person passing therethrough into the chamber 9. The body part I3 of each head Ill is formed with a row of spaced openings 24.

The liners I2 are of like form, of circular contour and each consists of three segment-shaped sections 25 of like form. Each section of each liner I2 is formed with oppositely disposed outwardly inclined end edges 26, a curved inner edge 21 and curved outer edge 28 of greater length than the edge 21. Each section of a liner I2 is formed with spaced openings 29. When the sections of a liner are assembled, the liner appears in the form of a circular disc formed with an axial opening. Each liner is to be arranged against the inner face of the body part I3, with the openings 29 registering with the openings 24, and with the wall of the axial opening of the liner forming an inward continuation of the axial opening in said body part. Each liner is detachably secured against the inner face of a body part I3, by the holdfast devices 30 extending through the registering openings 24, 29. The outer edge of each liner is beveled. The linings correspond in diameter to the diameter of body parts I3.

The grid element consists of a plurality of elongated bars 3| of arcuate contour in transverse cross section. When the bars 3I are assembled the grid element is in the form of a cylinder or drum. The bars 3| of a grid element are of like form and each includes a body part 32 and a lateral extension 33 at each end of said body part. The extensions 33 are of greater thickness than said body part. The inner side portion of each extension 33 constitutes a pad 34. The inner face of the outer side portion of each extension is formed with a rib 34 constituting a key. The outer face of the outer side portion of each extension 33 is formed with spaced cutouts to provide such outer side portion of the extension with alternately disposed high and low parts 34 34 respectively. The extensions 33 are formed with openings 35 which extend through the high parts 34 and to ribs 34 for a purpose to be referred to. The extensions 33 are provided with openings 35**, which extend through the low parts 34 and the ribs 34 for a purpose to be referred to.

The inner face of body part 32 has formed integral therewith a series of at least six spaced parallel lifters 36 of V-form extended inwardly of said face. The lifters 36 are of a length to extend from the inner end of one of the extensions 33 to the inner end of the other extension 33 on a body part. The inner face of the body part of each bar has formed integral therewith spaced reinforcing means 31 arranged between and integral with the sides of the lifters 36.

Each bar 3| of a grid element has its slots arranged between the lifters 33 and the portions of the extensions 33 which constitute the pads 34. That portion of the outer face of the body part 32 of a bar 3I between the pads 34 is inset with respect to the pads 34 to provide the bar with a recess 38 in its outer face.

As aforesaid when the bars 3| of a grid element are assembled, the said element is in the form of a cylinder or drum, and when so assembled the elongated edges of the bars are in abutting relation with the recesses 38 registering and coacting to form the outer surface of the grid element with an endless circumferentially extending groove for a purpose to be referred to. The side walls of the groove are formed by the extensions 33. The joints between the assembled bars 3i are indicated at 38 Figure 5. 1

A grid element, when employed as a part of the grinder structure, has the extensions on the body part 32 of each of its bars 3! seated on the horizontal legs 23 and abut the vertical legs 2| of the flanges iii of the heads I9. When the extensions 33 of the grid element seat on the legs of the flange l9 of the heads Hi, the ribs 34 seat in the grooves 22, the openings 35 register with the openings 23, and fastening devices 39 extend through the registering openings 23, 35 and detachably connect the grid element to the heads l0. When heads H],-liners l2 and grid element are arranged in connected relation as aforesaid the chamber 9 is formed. The grid element when set up in a manner as referred to provides what may be termed an inner screen for the passage of the ground material from the chamber 9.

There is associated with the grinder structure what may be termed an intermediate annular screen 43 which is arranged in the circumferentially extending endless groove provided by the recesses 38 and is flush with the outer faces of the pads 34. There is also associated with the grinder structure what may be termed an outer annular screen M which completely encompasses the screen 40 and extends onto the flanges 33. The screens 43, 4| are bodily carried with the revoluble grinder structure. The screens 40, 4| are secured to and in encompassing relation with respect to the grid element by spaced parallel adjustable securing bands 42, only one of which is shown. Each band consists of a flexible split annular body 43 having its ends provided with adjustable take up means 43. The bands are mounted on the screen M in encompassing relation with respect thereto, and then tightened up to hold the screen 39, 4| tightly clamped together and the screen 40 clamped to the grid element. The grid element also functions as a screen.

The slots or openings in a grid element for the passage of the ground material from chamber 9 are of larger size than the interstices of the screen 413. The interstices of the screen 4| are smaller than the interstices of the screen 40.

The interstices of the screen 4| are for passage of the material when it reaches the desired fineness. By the arrangement of the screens in the manner as aforesaid they are provided with openings of increasing width or diameter towards the axis of chamber 9.

The intermediate screen 45 preferably consists of a perforated annulus of the desired thickness formed of two halves welded together to provide a smooth surface and a protective cylinder for the outer screen 4!.

The slots or openings between the lifters 36 will allow material ground within the mill to escape outward and through the entire peripheral surface of the outer screen. The openings in the intermediate screen are made of any suitable size intermediate between the size of the openings between the lifters 33 and the size of mesh of the outer screen. The lifters 36, which also may be termed bar-like members are not attached singularly or in pairs to any outer perforated plate forming what may be a main supporting shell as will be found in certain forms of grinding mills; instead the main shell support and inner screen are made up of sturdy grid castings themselves, eachof which forms at least one-sixth of the circumference and are bound to the heads ID by interlocking and bolting giving rigidity Sim-- ilar to that of a one piece casting. The intermediate screen is in no way attached directly to the grid bars and there is little or no space between saidintermediate screen and said bars. The intermediate screen fits snugly around such bars and is arranged in the annular groove so as to be flush with the pads 34 and so as: to form an even surface for a snug fit of the outer screen entirely over the intermediate screen allowing little or no space between the intermediate and outer screens.

The trunnions iii are mounted in spaced parallel bearing structures 35. The mill will be driven in the direction of the arrows in Figure 5, that is anti-clockwise, by any suitable form of drive, and by way of example, the driving means is shown as consisting of a driven shaft 43 supported by a bearing 41. The shaft 4'5 carries a pinion 4'! which meshes with a gear 41 fixed to the outer end of one of the trunnions 85.

With reference to Figure 7, a modified form of means for attaching a grid element to a head In is shown, and which consists of a threaded bolt 54 extending through an opening Zl and formed at one end with an upstanding wedgeshaped head 55 arranged against a seat 2! and bearing on a low part 35 of an extension 33. Carried by the bolt 53 and binding against the outer face of the leg 2| is a clamping nut 56. The grid element, indicated at M, Figure '7, is detachably secured by this modified form of attaching means to the heads it by the bolt heads 55 bearing on the low parts 34 of the extensions 33, in connection with the keys 3-": engaging in the grooves 22 and the nuts 53 screwed home to bind against the outer faces of legs 2|.

With referenceto Figure 8, the modified form of flanged head 51 is of the same construction as a flanged head ill with the exception that the vertical leg 58 of the flange 59 of head 51 is formed on its inner face with a row of spaced squared recesses 60 (only one shown) in lieu of the tapered seats 2| on the inner face of leg 2| of flange l9. The leg 58 is formed with transverse openings 3! (only one shown) corresponding to openings Zl which communicate with the recesses 63. Otherwise than as stated the construction of the head 51 will correspond to that of a head Ill. The grid element shown by Figure 8 is indicated at N. Seated on the low parts 34 of the extensions 33 of the grid element are angled-shaped coupling members 62 (only one shown). Each member 62 consists of a vertical leg 63 which is arranged in a recess and a horizontal leg 34 mounted on a low part 33. The leg 63 is of greater thickness than the leg 64 and the depth of recess 30. The legs 63, 64 are formed with openings 65, 63 respectively, which register respectively with the openings 6|, and 35 Extending through each pair of registering openings 6!, 65 is a headed bolt 31 carrying on its inner end a clamping nut 38 for binding against the inner face of leg 33 of member 62. The leg 64 of member 62 is connected to the horizontal leg 39 of flange 59 by a rivet 13 which passes through a set of registering openings 23, 35 and 63, and is upset at each end. The bolts 31, clamping nuts 58, coupling members 52 and rivets ll] connect the grid element to the heads 51.

With reference to Figure 10, there is illustrated a hollow trunnion l5 peripherally shouldered at. [8. The trunnion I5 is mounted in a bearing 45 which abuts the shoulder l8. A leakproof ring H with a vertical and a beveled edge is mounted around the portion of largest diameter of the trunnion and is flush with shoulder I8. A stationary ring 12 is fixed to the inner vertical face of the bearing 45. A sloping hood 13 covers without touching the upright edge of ring II. The inner ring turns inside the stationary ring and prevents water splashes, corrosive solution or grit from getting into bearing surface from the operation of the mill.

As the mill revolves the lifters 36 act to prevent the charge from sliding; they carry the grinding elements around until they fall as a cataract from the upper part of the chamber 9 and on down onto other grinding elements and material mixed with them in the lower part of the chamber 9. The ground material works its way out through the grid openings between the lifters 35, then through the openings of the intermediate screen and discharge out through the interstices of the outer or finer screen. With reference to Figure 5, the discharge of the ground material from the grinder structure is indicated by the arrows and such discharge is at the lower part of such revolving structure, or in other words, such discharge is at the lower part of the outer screen 4|.

The feed entrance to the mill is through the hollow trunnions as indicated by the arrow in Figure 1.

When the outer end edges of the extensions 33 require grinding for a close fit, only those pro.- jecting portions 15 (Figure 3) on such edges need be adjusted, which will reduce work on hard manganese steel.

What I claim is:

1. In a grinding mill, a revoluble structure comprising a pair of disc-shaped head members, a trunnion carried by each member, at least one trunnion being hollow and comprising an axial intake, means supporting said trunnions, a cylindrical horizontal flange carried by each head and extending outwardly thereof, an annular vertical flange carried by each cylindrical flange at the outer end of the latter and disposed at right angles to said cylindrical flange, said cylindrical flange having an annular groove in its outer periphery, a plurality of inner screen bars arcuate in transverse section disposed between said heads, extensions carried by the opposite ends of said bars engaging said horizontal flanges and abutting against said vertical flanges, a key on each extension engaging in said groove, fastening devices engaging through said extensions, said keys and said cylindrical flanges, said fastening devices being remote from the grinding faces of said bars whereby said fastening devices will be out of contact with the material during the grinding of the latter, outstanding pads on said bars inwardly of the ends thereof, an outer screen between said vertical flanges and engaging on said pads, and an intermediate screen of less length than said outer screen and between said outer screen and the outer surfaces of said bars and between said pads.

2. In a grinding mill, a revoluble structure comprising a pair of disc-shaped head members, a trunnion carried by each member, at least one trunnion being hollow and comprising an axial intake, means supporting said trunnions, a cylindrical horizontal flange carried by each head and extending outwardly thereof, an annular vertical flange carried by each cylindrical flange at the outer end of the latter and disposed at right angles to said cylindrical flange, said cylindrical flange having an annular groove in its outer periphery, a plurality of inner screen bars arcuate in transverse section disposed between said heads, extensions carried by the opposite ends of said bars engaging said horizontal flanges and abutting against said vertical flanges, a key on each extension engaging in said groove, fastening means for securing said keys in said grooves, said fastening devices being remote from the grinding faces of said bars whereby said fastening devices will be out of contact with the material during the grinding of the latter, outstanding pads on said bars inwardly of the ends thereof, an outer screen between said vertical flanges and engaging on said pads, and an intermediate screen of less length than said outer screen and between said outer screen and the outer surfaces of said bars and between said pads.

3. In a grinding mill, a revoluble structure comprising a pair of disc-shaped head members, a trunnion carried by each member, at least one trunnion being hollow and comprising an axial intake, means supporting said trunnions, a cylindrical horizontal flange carried by each head and extending outwardly thereof, an annular vertical flange carried by each cylindrical flange at the outer end of the latter and disposed at right angles to said cylindrical flange, said cylindrical flange having an annular groove in its outer periphery, a plurality of inner screen bars arcuate in transverse section disposed between said heads, extensions carried by the opposite ends of said bars engaging said horizontal flanges and abutting against said vertical flanges, a key on each extension engaging in said groove, said vertical flanges having an annular recess in the inner faces thereof, outstanding pads on said bars inwardly of the ends thereof, an outer screen between said vertical flanges and engaging on said pads, an intermediate screen of less length than said outer screen and between said outer screen and the outer surfaces of said bars and between said pads, a pair of angle-shaped clamping members, said clamping members having one leg thereof engaging in a vertical flange recess and another leg thereof disposed in a horizontal position and engaging an extension outwardly of the pad, fastening devices engaging said horizontal leg, said extensions and said horizontal flanges, and fastening devices engaging said first leg of said clamping members and a horizontal flange to thereby hold said first leg of an angle clamping member in the recess of said vertical flange.

4. In a grinding mill, a revoluble structure comprising a pair of disc-shaped head members, a trunnion carried by each member, at least one trunnion being hollow and comprising an axial intake, means supporting said trunnions, a cylindrical horizontal flange carried by each head and extending outwardly thereof, an annular vertical flange carried by each cylindrical flange at the outer end of the latter and disposed at right angles to said cylindrical flange, said cylindrical flange having an annular groove in its outer periphery, a plurality of inner screen bars arcuate in transverse section disposed between said heads, extensions carried by the opposite ends of said bars engaging said horizontal flanges and abutting against said vertical flanges, a key on each extension engaging in said groove, said vertical flanges having an annular recess in the inner faces thereof, outstanding pads on said bars inwardly of the ends thereof, an outer screen between said vertical flanges and engaging on said pads, an intermediate screen of less length than said outer screen and between said outer screen and the outer surfaces of said bars and between said pads, and a pair of wedge-shaped bar fastening members having a portion thereof engaging in said recess of a vertical flange and another portion thereof abutting against an extension, each of said fastening members including a threaded part engaging through a. vertical 5 flange and a nut threaded onto said part.

GEORGE A. CAMPHUIS. 

